Crystal Reports Bind to a class in DLL

Message

   Hi

I am trying to bind Crystal Reports to an DLL - an existing custom data library, My library contains business object implementations.
I am using the "Database Expert", creating a new connection to an ADO.NET source, selecting the .dll from the my directory, and selecting the Class Name from the list of business entities that Crystal Report has detected from the assembly.
But when I try to expand the newly-added data source, "... no items found ..." is displayed instead of the properties of the business object.

I use similar aproach (BindingSource) when I bind my custom objects to the grid. 
Is there any way to to bind to classes defined in a .dll located in a folder ?
There are many examples if the class implementation is in my project code, but I could't figure out hot to do that, using classes from a DLL

Any suggestion/help is appressiated

regards,
Yakimo